取消动画

要取消对 requestAnimationFrame 的调用，你需要从上次调用时返回的 ID。这是你用于 cancelAnimationFrame 的参数。以下示例启动一些假设动画，然后在一秒钟后暂停它。

// stores the id returned from each call to requestAnimationFrame
var requestId;

// draw something
function draw(timestamp) {
    // do some animation
    // request next frame
    start();
}

// pauses the animation
function pause() {
    // pass in the id returned from the last call to requestAnimationFrame
    cancelAnimationFrame(requestId);
}

// begin the animation
function start() {
    // store the id returned from requestAnimationFrame
    requestId = requestAnimationFrame(draw);
}

// begin now
start();

// after a second, pause the animation
setTimeout(pause,1000);